A family in the United States has accused school administrators of using a school-issued laptop computer to spy on their son.

They have filed a lawsuit claiming a suburban school district in Philadelphia remotely activated the webcam installed in the computer to secretly take a photo of their son inside his home.

The school says the remote webcam function was simply a security measure that was installed in the 2,300 laptops given to students, but parents of children at the school are outraged by what they say is a violation of their privacy.

When the students at Harriton High School entered ninth grade, the school issued them a laptop to help with their studies.

Karen Gotlieb's 15-year-old daughter is in 10th grade at Harriton High School.

She says the school encouraged parents to talk to their children about proper online behaviour.

"The focus was 100 per cent put on the students," she said.

"This is something reasonable that as parents we teach our kids: to behave appropriately, to behave themselves like gentlemen and young ladies when they're on the computer, to not do anything to damage their future, that these are permanent things.

"We never saw the school district as the predator here."

Ms Gotlieb says she is alarmed to hear school officials have the ability to remotely access the web cam on her daughter's laptop and take a picture.

"First of all there's a tremendous right to privacy issue that's of concern," she said.

"In no way did I consent to this when I signed the contract for the use of the laptop. It was never made clear to the parents that this was a capability that the laptops even had.

"And on a simplistic level, we're talking about high school students bringing laptops home.

"Typically, high school students here are going to use those in the privacy of their own bedroom to do their homework in the evenings and late into the night.

"Naturally we feel that we have a sense of privacy when we are in our own home, in our bedroom with the door locked.

"And now we're finding out that at any given moment, somebody in our school district was able to remotely activate that webcam and watch whatever it was that was going on in our home at the time."

Parents launch lawsuit

The issue came to light this week when the parents of another of the school's students, Blake Robbins, filed a lawsuit.

They claim an assistant principal at the school confronted the student for "improper behaviour" late last year and cited a photograph taken by the webcam as evidence.

It is not known what improper behaviour was alleged.

"Now that the issue has been coming to light ... several students have reported that over the past year and a half that they've had the school-issued laptops, that all of a sudden the green blinking light would come on the webcam and they have joked that somebody in the district was watching them," Ms Gotlieb said.

"So what has been a joke among the students for the past year-and-a-half all of a sudden today is being taken a little bit more seriously."

The local school district has today acknowledged in a statement that the laptops it issued do have a remote webcam function as a security measure.

The statement said the remote camera feature was only activated upon a report of a suspected lost, stolen or missing laptop and that the camera was limited to only taking still images.

Ms Gotlieb says she does not accept this explanation.

"I think it's utterly ridiculous. In fact I'm not aware that this young man who was caught up in this situation that has brought all this to light had reported his laptop stolen or lost," she said.

"Therefore if the school district's theory on why the technology exists in the laptop is true, why would they have been clicking onto this young man's computer? It makes no sense."

Ms Gotlieb says she is still unsure whether she will be joining in the lawsuit and is still trying to digest the information.

The school district says the remote camera feature has been deactivated effective today.

Privacy advocates say this case serves as a reminder to anyone who is given a laptop or similar device that the person making the gift might be keeping an eye on you.